Rat guard

ABSTRACT

A rat guard for ships&#39;&#39; hawsers and the like. A polygonal barrier plate has a bottom portion and has a top portion with two steeply converging edges meeting at a narrow vertex at the very top. A slot in the bottom portion extends up to a round hawser-engaging edge at about the center of gravity. A self-closing door is pivoted to the plate near the upper end of said slot. It is urged to a normally closed position by its weight and its relation to its pivot, and it then lies athwart the slot, with an edge mating with the round hawser-engaging edge to encircle the hawser. A stop or other holding means secured to the plate can hold the door about 180* away from its said normal position, where a portion lies across the slot&#39;&#39;s upper end so that it will be engaged by a hawser that has entered the slot and thereby caused to swing around its pivot to enclose the hawser between itself and the plate.

United States Patent Haglund et al.

[ 1 Aug. 21, 1973 Primary dm il:l8rM1liO1lB11Ch!f AssistantExaminer--Gregory W. OConnor Attorney-Owen, Wickersham & Erickson 1 1ABSTRACT A rat guard for ships hawsers and the like. A polygonal barrierplate has a bottom portion and has a top portion with two steeplyconverging edges meeting at a narrow vertex at the very top. A slot inthe bottom portion extends up to a round hawser-engaging edge at aboutthe center of gravity. A self-closing door is pivoted to the plate nearthe upper end of said slot. It is urged to a normally closed position byits weight and its relation to its pivot, and it then lies athwart theslot, with an edge mating with the round hawser-engaging edge toencircle the hawser. A stop or other holding means secured to the platecan hold the door about 180 away from its said normal position, where aportion lies across the slots upper end so that it will be engaged by ahawser that has entered the slot and thereby caused to swing around itspivot to enclose the hawser between itself and the plate.

11 Claims, 7 Drawing Figures Patented Aug. 21, 1973 3,753,416

2 Sheets-Sheet l INVENTOR5 BERNARD F. HAGLUND BY ROBERT M. SALVAREZZAATTORNEYS Patented Aug. 21, 1973 3,753,416

2 Shoots-Sheet 2 IN VENTORS BERNARD F. HAGLUND BY ROBERT M. SALVAREZZAATTORNEYS RAT GUARD BACKGROUND OF THE INVENTION This invention relatesto an improved rat guard, providing surer closure action, bettercentering action, easier release action, and improved protection fromrats.

Rat guards are used around the hawsers of ships to prevent rats andother rodents on shore from boarding the ships by simply walking alongthe hawsers. Heretofore, rat guards have generally comprised largecircular discs which have had to be installed on the ships hawsers byhand under inconvenient circumstances. Since they have been large discs,their curvature per foot of circumference has been relatively flat, sothat large rats have often been able to place their forelegs on theupper edge, then to jump and get all four legs on the upper edge, andthen jump down on the other side to the hawser and so board the ship[ Ininstalling rat guards, reliance has typically been made on making thecircular disc in two pieces which can be swung apart and which have tobe bolted together. This bolting together is inconvenient and it makesit difficult to put on and take off the rat guard.

BRIEF SUMMARY OF THE INVENTION The rat guard of this invention may use acircular disc if that is desired, but preferably it uses a polygonalbarrier plate with two steeply converging upper edges meeting at thenarrow vertex at the very top. The vertex is so narrow that a rat cannotget all four of its legs on it, and therefore even if the rat is verylarge, it is extremely unlikely to be able to negotiate passage beyondthe rat guard.

Whether round or polygonal, the rat guard of this invention ischaracterized by an assembly which makes for very easy installation andremoval. The barrier plate has a slot extending up from the bottom abouthalfway to a round hawser-engaging edge. A self-closing door is pivotedto the plate near the upper end of the slot and to one side of it and isprovided with a weight which tends to cause it to move into a positionclosing the door around the other side of the hawser, with a roundededge portion being provided to encircle the hawser in combination withthe hawser-engaging edge at the upper end of the slot at the plate.Prior to installation, the door is cocked by swinging it around itspivot until its edge engages a stop. At that point, the center ofgravity of the door lies on the side of the vertical line through thepivot where the weight of the door urges the door against the stop,rather than causing the door to move into the closing position. The dooris made so that in this cocked position an edge portion lies across theupper end of the slot where it is engaged by a hawser that has enteredthe slot. This happens when the rat guard is dropped down by ropes ontothe hawser, and a pair of brackets is provided for enabling theattachment of ropes for just this purpose. These ropes and the door are,of course, placed on the ship side of the rat guard, so that the ratfrom shore has no access to the brackets or ropes. When the rat guard isthen lowered into place against the hawser, the hawser engages theportion of the door lying across the slot and pushes on the door so asto swing the door away from the stop and move the center of gravity pastthe vertical line through the pivot, so that the door swings into itsclosed position around the hawser. A second stop may be provided toengage the door on closure a little ahead of the normal rest position sothat the door is held more firmly, by its weight, around the hawser.When it is desired to remove the rat guard from the hawser, the ratguard is lifted by the ropes, and the hawser then swings the door farenough away from the second stop to enable extraction of the hawser fromthe slot. Then the door swings back to its normally closed position. Itis recocked before reuse.

Other objects and advantages of the invention will appear from thefollowing description of a preferred embodiment and from the drawingsthereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a simplified view in perspective of a docked ship with twohawsers, each having a rat guard embodying the principles of theinvention located on the hawser and held at a desired location by ropesattached to the rat guard and to a suitable member on the ship.

FIG. 2 is a view in front elevation of a rat guard embodying theprinciples of the invention with the holding ropes broken off in orderto conserve space.

FIG. 3 is a view in perspective looking from the rear of the rat guardwith the self-closing door in cocked position and with the hawserentering in the slot.

FIG. 4 is a view similar to FIG. 3 in which the hawser is moving thedoor away from its cocked position toward a position where the center ofgravity of the door will cross the vertical line through the pivot.

FIG. 5 is a similar view with the door moved into its locked positionand holding the rat guard around the hawser.

FIG. 6 is a similar view showing how the rat guard can be raised up fromthe hawser to cause the hawser to swing the door open enough to enablethe hawser to be withdrawn from the slot.

FIG. 7 is a fragmentary enlarged view in section through the pivot.

DESCRIPTION OF A PREFERRED EMBODIMENT As shown in FIG. 1, a docked ship10 is held to the wharf by hawsers, two hawsers or mooring lines 11 and12 being shown here. If nothing more were done, rats, mice and otherrodents could walk along the large hawsers and get aboard the ship, andthey have often done this.

The present invention provides that each hawser 11, 12 be equipped witha rat guard 15, 15' which fits around the hawser 11, 12 and excludesrats by providing a barrier around which they cannot pass. Two guideropes 16 and 17 and 16', 17' are used for holding the rat guard 15, 15'in the proper position and are also used in installing and withdrawingthe rat guard 15, 15

on and from the hawser 11, 12.

The rat guards 15 and 15' are identical, and FIG. 2, a view in frontelevation, shows the rat guard 15 as it is seen by the rat, with theexception that the hawser 11 or 12 is not shown in place. The rat guard15 may be any size desired, but is preferably made large enough, say aheight of 18 to 20 inches above the hawser 11, to be beyond the stretchof a large rat and to prevent a rat from seeing over it or knowingenough what is beyond it to enable it to jump accurately over it.

The rat guard 15 of this invention may be made as a circular disc, butit preferably comprises a barrier plate of the polygonal shape shown inthe drawings, because with a broad circle, a rat can put its front feetup on the top, lift the other two feet up, steady itself, and jump down.However, with the polygonal shape shown, the two upwardly convergingedges 21 and 22 of the plate 20 meet at a narrow vertex 23 and the edges21 and 22 are both too steep to enable the rat to hold on to either ofthem and get around the plate 20. The plates center of gravity keeps thevertex 23 at the top.

The vertex 23 is so narrow that the rat cannot get all four of its feetup there, in fact, it is doubtful whether it could get more than one, sothat it cannot achieve a stable position atop the vertex 23, from whichit might be able to progress further. Although a rat may still try tojump over the barrier plate 20, that usually results in missing thehawser 11 and falling into the water, and rats do not attempt suchchances. The balance of the plate 20 is such that if a rat or otherrodent should attempt to climb over or around it, the plate 20 rolls ortips toward him in response to his weight, dropping him into the waterbelow. The plate 20 is more stable in gusty winds than a circular discand is much less liable to be bent out of shape by the winds.

The plate 20 may be shaped, as shown, in a generally pentagonal shapewith sloping bottom sides 24 and 25 and a bottom edge 26 interrupted bya guide slot 27 which may be wider at the bottom than at its upper edge,which lies near or at the center of gravity of the plate 20 and where acircular upper portion 28 is provided to engage the hawser. The guideslot 27 enables crewmen easily to place the rat guard 15 on the hawser11. The edges of the plate 20 and of its slot 27 may be folded over toprotect crewmen from being cut.

Secured to the plate 20 is a self-closing door or ropeenclosing member30, which is mounted on a pivot assembly 31. As shown in FIG. 7, thepivot assembly 31 may include a bolt 32 having a head 33 on the wharfface of the plate 20, a nut 34, a metal spacing washer 35 next to theplate 20, a metal washer 36 next to the nut 34, and a fiber washer 37between the washer 35 and the door 30. The fiber washer 37 providesfriction helping to prevent premature closing of the cocked door duringinstallation. The door 30 may be shaped in any manner desired butpreferably is provided with a round edge portion 38 adapted to engagethe lower side of the hawser 11 and cooperate with the edge portion 21to enclose the hawser 11 and prevent the passage of rodents there. Theself-locking door 30 prevents the winds or tidal movement fromdislocating the rat guard 15 and detaching it from the hawser l1.Preferably, the door 30 is also shaped to give a good closure across thebottom of the slot 27 and to provide near the portion 38 a sloping edge39 and adjacent portions that project in the manner shown in FIG. 3 intothe slot 27 when the door is set to a cocked position. Preferably, also,the door 30 has a weight 40 to enable concentration of the door's weighttoward a single location, though the door 30 may be shaped to providethe needed location for the center of gravity, the weight 40 ispreferably located distant from the pivot 31 near an edge 41.

The door 30 is set to a cocked position with the aid of the weight 40and a stop 42 provided on the plate 20. In this instance the stop 42 mayalso serve as a bracket for the rope 17 with another bracket 43 beingprovided for the other rope 16 which does not act as a stop. The stop 42could, of course, be a separate member from the rope-holding bracket,but this expedient is economical. The stop 42 holds the door 30 againstrotating in one direction, and that direction is chosen to be the one inwhich the weight is then urging the door 30 against the stop. The door30 is so shaped and weighted that when it is rotated on its pivot 31away from the stop 42, as it can be by lowering it onto the hawser 11 sothat the hawser 11 in effect presses up on the door 30, the door 30swings around to a position (FIG. 4) where the center of gravity of thedoor 30 as a whole (including the weight 40) passes beyond the verticalaxis through the pivot 31, and then the weight 40 makes the door 30swing around to close around the hawser, as shown in FIG. 5. To insuregood closure, this final position may be a position somewhat short ofthe position to which the door 30 would actually be urged by its weight40, with a second stop member 44 holding it there and with the weight 40urging the door 30 firmly against the second stop member 44. To givebetter contact of the door 30 with the stop 42, the edge 45 that engagesthe stop 42 is partially folded to provide a contact flange 46;similarly the edge 47 which engages the stop 44 is folded to provide acontact flange 48. Comers 49 and 50 are preferably folded up somewhat togive better swinging action.

The device is easily installed by using a pair of ropes 16 and 17 aboutfifteen to twenty-five feet long to lower the rat guard 15 along thehawser 11 while keeping it high enough so that, while the hawser l1enters the slot 27 as shown in FIG. 3, the edge 39 does not touch thehawser 1 1. To give better action at this stage, the brackets 42 and 43are aligned on a line making an angle with the vertical axis of theplate 20, sloping down from the bracket 42 to the bracket 43. When thedesired position is reached, the ropes 16 and 17 are lowered orslackened so that the hawser 11 then engages the edge 39 and swings thedoor around the pivot 31, (FIG. 4), and then the weight 40 swings thedoor 30 into the closed position shown in FIG. 5. The ropes 16 and 17are left slack and tied to the ship.

When it is desired to remove the rat guard 15 from the hawser 11, theropes 16 and 17 are untied and pulled up, and the force of the door 30against the hawset 11 swings the door 30 around until the hawser 11 canbe withdrawn from the slot 27, and then the door 30 falls back into itsnormally closed position. The door 30 is later recocked by hand, usuallyaboard ship.

When a smaller rat guard is used on small cabin cruisers and yachts, asmaller aperture and slot are provided and additionally locking lugs forthe door enable a padlock to be used for security from theft.

To those skilled in the art to which this invention relates, manychanges in construction and widely differing embodiments andapplications of the invention will suggest themselves without departingfrom the spirit and scope of the invention. The disclosures and thedescription herein are purely illustrative and are not intended to be inany sense limiting.

We claim:

1. A rat guard for ships hawsers and the like, including in combination:

a large barrier plate having a bottom portion with a generally verticalslot affording entry to a said haw- 8:11 and extending up to a roundhawser-engaging 8.

a self-closing closure door pivoted to said plate near the upper end ofsaid slot and urged to a nonnal position by its weight and the relationof its center of gravity to its pivot, where it lies athwart said slotwith an upper edge mating with said hawserengaging edge to encircle asaid hawser, and

retaining means for said door secured to said plate for holding saiddoor cocked away from its said normal position with a portion of saiddoor lying across the upper end of said slot for engagement by a hawserthat has entered said slot,

said door being actuated by engagement of said hawser when said door isin its cocked position, for causing said door to swing around its pivotto enclose said hawser snugly between itself and said plate.

2. The rat guard of claim 1 wherein said barrier plate has an upperportion above said hawser-engaging edge comprising two steeply slantededges meeting at a narrow vertex at the top.

3. The rat guard of claim 1 having a pair of brackets for attachment ofa rope to each said bracket, for placing said rat guard on said hawserand for removing it therefrom.

4. A rat guard for ships hawsers and the like, including in combination:

a large barrier plate having a generally smooth wharfside face and ashipside face, a bottom portion with a generally vertical tapered slotaffording entry to a said hawser and extending up to a roundhawserengaging edge,

a self-closing hawser closure door on the shipside face of said plate,pivoted to said plate near the upper end of said slot and having aweight thereon urging said door to a normal position where it liesathwart said slot with an upper edge mating with said hawser-engagingedge to encircle snugly a said hawser, and

stop means for said door secured to said plate and holding the door,when rotated against said slot, cocked away from its said normalposition with a portion of said door lying across the upper end of saidslot with a diagonally extending edge for engagement by a hawser thathas entered said tapered slot,

said door being actuated by engagement with said hawser, when said dooris in its cocked position, for causing said door to swing around itspivot to enclose said hawser between itself and said plate.

5. The rat guard of claim 4 having a pair of brackets on said shipsideface above said door for attachment of a rope to each said bracket, foremplacing and removing said rat guard on a said hawser.

6. The rat guard of claim 5 wherein one said bracket functions also assaid stop means.

7. The rat guard of claim 4 having second stop means for stopping saiddoor short of the position to which it would normally be urged by saidweight, when swung around a said hawser.

8. The rat guard of claim 4 wherein said barrier plate has a narrowvertex at its very tip and two steeply inclined edges leading downtherefrom.

9. A rat guard for ships hawsers and the like, including in combination:

a polygonal barrier plate having a top portion with two steeplyconverging edges meeting at a narrow vertex at the very top and a bottomportion having a slot extending up from a bottom edge to a roundhawser-engaging edge at the upper end of said slot,

a self-closing door pivoted to one side of said plate near the upper endof said slot and weighted toward a normal position by a weight securedthereto and by the relation of its center of gravity to its pivot, lyingin said normal position athwart said slot with a rounded edge portionmating with said round hawser-engaging edge to encircle a said hawsersnugly, and

a stop for said door secured to said plate on the same side as said doorand engaging an edge of said door when said weight is swung over centerin one direction to hold it away from its said normal position, aportion of said door then lying across the upper end of said slot forengagement by a hawser that has entered said slot,

the pressure of a hawser on said door when said door engages said stopcausing said door to rotate around its pivot and place its said weightover center in the other direction and then to fall down and to enclosesaid hawser between itself and said plate. 1

10. The rat guard of claim 9 having two brackets secured to said plateon the same side as said door, having means for attachment of a rope toeach said bracket, one said bracket also comprising said stop.

11. The rat guard of claim 10 having a second stop limiting the swing ofsaid door away from the firstmentioned said stop.

t s a a a

1. A rat guard for ships'' hawsers and the like, including incombination: a large barrier plate having a bottom portion with agenerally vertical slot affording entry to a said hawser and extendingup to a round hawser-engaging edge, a self-closing closure door pivotedto said plate near the upper end of said slot and urged to a normalposition by its weight and the relation of its center of gravity to itspivot, where it lies athwart said slot with an upper edge mating withsaid hawser-engaging edge to encircle a said hawser, and retaining meansfor said door secured to said plate for holding said door cocked awayfrom its said normal position with a portion of said door lying acrossthe upper end of said slot for engagement by a hawser that has enteredsaid slot, said door being actuated by engagement of said hawser whensaid door is in its cocked position, for causing said door to swingaround its pivot to enclose said hawser snugly between itself and saidplate.
 2. The rat guard of claim 1 wherein said barrier plate has anupper portion above said hawser-engaging edge comprising two steeplyslanted edges meeting at a narrow vertex at the top.
 3. The rat guard ofclaim 1 having A pair of brackets for attachment of a rope to each saidbracket, for placing said rat guard on said hawser and for removing ittherefrom.
 4. A rat guard for ships'' hawsers and the like, including incombination: a large barrier plate having a generally smooth wharfsideface and a shipside face, a bottom portion with a generally verticaltapered slot affording entry to a said hawser and extending up to around hawser-engaging edge, a self-closing hawser closure door on theshipside face of said plate, pivoted to said plate near the upper end ofsaid slot and having a weight thereon urging said door to a normalposition where it lies athwart said slot with an upper edge mating withsaid hawser-engaging edge to encircle snugly a said hawser, and stopmeans for said door secured to said plate and holding the door, whenrotated against said slot, cocked away from its said normal positionwith a portion of said door lying across the upper end of said slot witha diagonally extending edge for engagement by a hawser that has enteredsaid tapered slot, said door being actuated by engagement with saidhawser, when said door is in its cocked position, for causing said doorto swing around its pivot to enclose said hawser between itself and saidplate.
 5. The rat guard of claim 4 having a pair of brackets on saidshipside face above said door for attachment of a rope to each saidbracket, for emplacing and removing said rat guard on a said hawser. 6.The rat guard of claim 5 wherein one said bracket functions also as saidstop means.
 7. The rat guard of claim 4 having second stop means forstopping said door short of the position to which it would normally beurged by said weight, when swung around a said hawser.
 8. The rat guardof claim 4 wherein said barrier plate has a narrow vertex at its verytip and two steeply inclined edges leading down therefrom.
 9. A ratguard for ships'' hawsers and the like, including in combination: apolygonal barrier plate having a top portion with two steeply convergingedges meeting at a narrow vertex at the very top and a bottom portionhaving a slot extending up from a bottom edge to a round hawser-engagingedge at the upper end of said slot, a self-closing door pivoted to oneside of said plate near the upper end of said slot and weighted toward anormal position by a weight secured thereto and by the relation of itscenter of gravity to its pivot, lying in said normal position athwartsaid slot with a rounded edge portion mating with said roundhawser-engaging edge to encircle a said hawser snugly, and a stop forsaid door secured to said plate on the same side as said door andengaging an edge of said door when said weight is swung over center inone direction to hold it away from its said normal position, a portionof said door then lying across the upper end of said slot for engagementby a hawser that has entered said slot, the pressure of a hawser on saiddoor when said door engages said stop causing said door to rotate aroundits pivot and place its said weight over center in the other directionand then to fall down and to enclose said hawser between itself and saidplate.
 10. The rat guard of claim 9 having two brackets secured to saidplate on the same side as said door, having means for attachment of arope to each said bracket, one said bracket also comprising said stop.11. The rat guard of claim 10 having a second stop limiting the swing ofsaid door away from the first-mentioned said stop.